﻿<p><i>IfcReferent</i> defines a position at a particular offset along an alignment curve.</p>

<p>Referents may be used for several scenarios:</p>
<ul>
<li>positioning physical elements at common locations along an alignment curve (e.g. bridge piers)</li>
<li>indicating transitions for cross-sections (e.g. beginning of curvature where road is relatively flat, maximum curvature having super-elevated cross-slope to accomodate design speed)</li>
<li>indicating broken chainage where distance measurements reset or reverse directions</li>
<li>indicating domain-specific design parameters (via property sets) at locations along an alignment curve</li>
</ul>